Method for making corrugated board



April 23, 1929. H. A. cuMr-ER METHOD FOR MAKING CORRUGATED BOARD Filed Aug. 16. 1926 Cil Patented Apr. 23, 1929.`

twain/ic4 vUNITED STATES PATENT OFFICE.

HARRY A. CUMFER, OF CHICAGO, ILLINOIS. Y

METHOD FOR MAKING CORRUGATED BOARD.

'Application mea August 1s, 192e. serial No. 129,384.

' uniting said corrugated strips to uncorrugated strips fed between the corrugated strips and united thereto. Adhesive is applied between each corrugated strip and each uncorrugated strip only. The product at this stage comprises a unit exhibiting in cross section two outer corrugated strips and two separated central strips. Surface sheets may then be united with the corrugated strips. Immediately subsequent to the point at which this built-up unit leaves the corrugating machine, a stripper separates the two independent central strips from each other, producing two Y separate units of corrugated board, each comprising uncorrugated surface sheets and a cor-` rugated center.

As the specific embodiment of the present invention, the sheets to be corrugated are acted upon by the corrugating elements while said sheets are moving toward the horizontal in a plane disposed at an angle to the horizontal, thus reducing friction and rubbing of the corrugating'elements against the side walls of the corrugations and eliminating strains normally incident to the corrugating of asheet while it is moving in a horizontal plane.

Many advantages and objects of theinvention will be hereinafter more fully described.

In the drawings, p l Fig.` 1 is a diagrammatic side elevational view of the apparatus;

Fig. 2 is a cross sectional view of the product before being separated; and

Fig. 3 is a cross sectional view taken through oneof the separated units of corrugated board. E Referring .more inedetail to the drawings, there are two sets of oppositely disposed assemblies functioning to simultaneously corrugate two sheets and cause them to be united to central sheets.

Referring more in detail tothe upper assembly, 1 designates sprockets mounted on each end of a shaft 2'. These sprockets are adapted to Vhave meshing engagement with endless elements 3. Extending transversely of the assembly and carried by the endless elements are a plurality of connected corrugating bars 4 provided on their upper surfaces withthe corrugating ribs 5. The endless elements 3 mesh on their opposite ends with the sprockets 6 mounted on shaft 7. The arrangement is such that the sprockets 6 are of a smaller diameter than the sprockets 1, the upper edges of both sets of sprockets lying in substantially a horizontal plane.

`The purpose of this will now be described.

Disposed immediately adjacent the sprockets 6 and adapted to have meshing engagement with the corrugating bars 4 is a corrugating roll 8 mounted on the shaft-9. A strip of material designated 10 is fed between the corrugating bars 4 and the'corrugating roll 8, and due to the decreased diameter of the sprockets 6, the corrugating bars 4 and the corrugating roll 8 act on said sheet while 1t is moving in a plane disposed at an angle from the horizontal.` One advantage of corrugating a sheet while it is moving in a plane at a substantial angle from the horizontal is to materially decrease friction and strain'and prevent the corrugating elements from rubbing against the side walls of the corrugations, which first produces straining and distortion of the libres and eventually weakening the side walls.

The corrugated sheet is stripped from the roll 8 by means of the stripping fingers 11 disposed in circumferential grooves in the surface of the corrugating roll S. This newly corrugated sheet may have a tendency to flatten, and to avoid this the newly corrugated sheet is caused to travel downwardly in registering relation with the corrugating ribs 5 on the bars 4. To insure this engaging relation between the newly corrugated sheet and the corrugating bars 4, I may provide spring plates 12 held by suitable cross bars 13, as illustrated.

At this stage, two corrugated sheets are being simultaneously fed downwardly and upwardly toward a point of meeting in a horizontal plane. i

Between each set of corrugated strips 1noving toward each other, there is introduced two strips 14 of plain uncorrugatedmaterial. Suitable adhesive is applied to the lower surface et the lower sheet and the upper surtace of the upper sheet by the adhesive apphyingl means designated diagrammatically at 15. No adhesive is applied between the two uneorrugated strips.

The tour strips are then ted between the -means ioi" imposing` pressure, shown dial relation with the cori-ucatinol bars mounted on the endless elements to prevent flattening or spreading` ofthe coirugations tor a considerable distance in t-lie travel ot the unit. i The unit then strips 'from the corrugating elements t, and at this stage comprises a unit which in cross section exhibits two outer corrugated sheets and two central uncorrugated sheets, which latter are adhesively united to the corrugated strips but are separate relative to each other. lt mayY then he desirable to apply surface sheets to the corrugated sheets.k W here this is desired, surface strips, shown at 17, to the surface oi which may be applied adhesiveby the means illustrated diagramn'iatically at 18, are ted and united with the corrugated' strips by means ot' the pressure exerted by the rolls 19 and endless belt 20. lt is understood, ot' course, that the illustrations in the drawings are diagrammatic to illustrate the principle ot the invention without unnecessarily complicatingthe drawings.

After leaving the pressure imposing means 19, the unit thus produced comprises in cross section a siX-ply sheet (Fig. 2), exhibiting two outer uncorrugated surface sheets, two corrugated sheets attached thereto, and two central sheets attached to the corrugated sheets but separate relative to each other.

Now as a feature oily the present invention, a` se )aratingl device, shown diagrammatically at. 21, is interposed between the two separate uncorrugated, inner sheets, thus separating` said composite corrugated unit into two separated units, each comprising sur- 'liace sheets and a central corrugated core, as shownin Fig. 5.

The many advantages ot' the present invention 'resulting from the simultaneous production ot two complete corrugated units on a single machine will be obvious, but economy in operation and maximum product-ion are two advantages which may beparticularly stressed.

lt is understood that thepresent invent-ion is not limited tothe production of a six-ply sheet, separating into two separate three-ply sheets, but the invention contemplates the production of corrugated board of any numbei ot plies to be separated into the individual corrugated units wherever the principle ot' the invention is utilized.

As a feature ot the presentinvention, the adhesive preferably used, is one which possesses waterprooling qualities such tor instance, as bitumen and more particularly asphalt and the like. lt will be immediately apparent to those skilled in the art that by applying,` a coating` of adhesive possessing,` waterproofing qualities to desired surfaces ol the plain sheet or sheets, that water repellant barriers or areas are thus provided throughout the composite corrugated sheet in the form ol continuous lilms. ln addition, the outer surfaces oit the corrugated board may be preferably Vtree troni any waterproofing material, thus permitting the absorption or a certain amount ot moisture, but preventing` this moisture from penerating into the body ot the composite board.

The invention also contemplates that the corrugated sheets may have been previously impregnated or saturated with the water rcpellant material, although tor the purpose ot this invention, it is desiiable that the sheets to be corrugated, be relatively dry to avoid sticking and gumming of the corrugated torniingmeans.

l claim as my invention:

1. A process oit making corrugated board comprisingfeeding a plurality of sheets ot material to be corrugated in a plane disposed at an angle from the horizontal, acting on said sheets while moving in said plane to pioduce corrugations therein, introducingbetween. oppositely disposed corrugated sheets two uncorrugated sheets, uniting` each ot the corrugated shets to one surface oit each ol the uncorrugated sheets introduced tlieiebctween, to produce a structure in which the uncorrugated sheets are separate relative to each other, and then separating the built-up unit into smaller units by separating same between the unattached uncoriugated sheets.

2. A process ot making corrugated board con'iprising feedingv a plurality ot sheets ot material to be corrugated in a plane disposed at an angle from the horizontal` acting' on said sheets while movingin said plane to produce corrugations therein, causing said corrugated sheets to be carried forward in such a manner as to prevent collapsinkg` of -the newly formed corrugations, introducing between oppositely disposed corrugated sheets two uncorrugated sheets, unitingneach of the corrugated sheets to one surface ot each oie. the uncoiiugated sheets introduced l therebetween, to produce a structure in which the uneorrugated sheets are separate relative to each other, and then separating the builtup unit into smaller units by separating saine between the unattaehed uncorrugated sheets.

3. A process ot making corrugated board which comprises simultaneously and sepa- Vrately corrugating a plurality of sheets of Iii tl (l material, introducing between oppositely disposed corrugated sheets uncorrugatedsheets, adhesively uniting 'a separate uncorrugated sheet-to ya surface of each of the corrugated sheets to produce a structure in which the uncorrugated sheets are disposed in face to face unattached relationship, and finally separating the built up unit into sn'ialler units by separating same between the unattached uncorrugated sheets.

4. A process of making corrugated board which comprises simultaneously and separately corrugating a plurality of sheets of material, introducing between oppositely disposed corrugated sheets uncorrugated sheets, adhesively uniting a separate uncorrugated sheet to a surface of each ofthe corrugated sheets to produce a structure in which the uncorrugated sheets are disposed in Ytace to tace unattached relationship, thereafter adhesively uniting a second uncorrugated sheet to the exposed portions of each corrugated sheet, and finally separating the built up unit into smaller units by separating same between the unattached uncorrugated sheets.

5. A process of making corrugated board comprising Jfeeding a plurality of sheets of material to be corrugated in a plane disposed at an angle from the horizontal, acting on said sheets while moving in said plane to produce corrugations therein, introducing between oppositely ydisposed corrugated sheets uncorrugated sheets, uniting each of the corrugated sheets to one surface of each of the uncorrugated sheets introduced therebetween, to produce a structure in which the uncorrugated sheets are separate relative tov each other, and then separating the built-up unit into smaller units by separating same between the unattached uncorrugated sheets.

6. A process of making corrugated board which comprises simultaneously and separately feeding separate sheets ot material. to be corrugated in planes above and below the horizontal to the horizontal, acting on said sheets while moving in said planes to produce corrugations therein, introducing between oppositely disposed corrugated sheets uncorrugated sheets, adhesively uniting a separate uncorrugated sheet to a surface oi each of the corrugated sheets to produce a structure in which the uncorrugated sheets are disposed in face to face unattached relationship, and finally separating the built-up unit into smaller units by separating the same between the unattached uncorrugated sheets.

HARRY A. CUMFER. 

